Infusion systems and medication delivery devices, such as infusion pumps, are well known and widely used throughout the world today. Intravenous infusion pumps were developed decades ago to pump medicaments, nutrients or other fluids through tubing to a patient in connection with treatment of a medical condition. Infusion pumps include peristaltic pumps, roller pumps, or expulsor pumps, for example. Many of these infusion pumps operate by governing the movement of fluid through delivery tubing by selectively occluding portions of the tubing by depressing a valve or mechanism against the tubing. For example, in some designs the mechanism of a pump selectively engages the tubing against a pressure plate in a peristaltic fashion to force fluid through the tubing.
Various infusion pumps deliver medication from either a disposable medication cassette reservoir or from a disposable administration set having a remote fluid reservoir. Accordingly, these disposables include a pressure plate top surface that is detachably coupled to a bottom surface or chassis of a pump control module. The chassis can be provided with a sensor module with a channel on one surface. A sensor can be provided as part of the channel and detects the presence of air or gas bubbles in tubing. Tubing is provided with and attached to the pressure plate top surface and, when coupled to the pump control module, seats in the channel of the sensor module. The outer wall of the tubing thus makes contact with the channel and the channel sensor can detect the presence of air or gas bubbles in the tubing when fluid is pumped, via the tubing, from the cassette reservoir or the remote fluid reservoir by the control module when the pressure plate is coupled to the control module.
When the pressure plate is properly aligned and connected to the pump control module chassis, a prescribed dose of medication is delivered at a controlled rate to a patient through the tubing connected to the pressure plate. However, if the tubing is improperly seated, blocked, kinked or otherwise impeded by, for example, improper alignment of the pressure plate and pump control module, the patient likely would not receive the prescribed medication, at all or in an intended volume, leading to potentially serious consequences.
Improvements to these types of infusion pump arrangements are desired. For example, ensuring proper alignment of the pressure plate and pump control module is a necessity to the provision of effective infusion pumps. Due to the importance of delivery accuracy and precision in both of the aforementioned cassette-type arrangements and administration-type arrangements, any improvements in these areas would be desirable and a design which can better optimize the interaction and alignment of the pump and pressure plate features would be advantageous.
Therefore, there is a need for improved methods and apparatus for the attachment and alignment between pressure plates and pump control modules in infusion pumps.